Catalytic Methods for the Production of Sugar Esters

2021 ◽  
Vol 21 (6) ◽  
pp. 424
Author(s):  
M. A. Otache ◽  
R. U. Duru ◽  
O. Achugasim ◽  
O. J. Abayeh

Nowadays, Sugar esters (SEs) have become the focus of researchers due to their biocompatibility and extensive industrial applications as surfactants. This trend provides new methods and opportunities for the development of green synthetic chemistry. Taking the above into consideration, a critical review presented in this work emphasized the efficiency of catalyzing the synthesis of SEs with minimal hazardous by-products. These catalytic media have been employed with various impacts involving chemical, biological, and other catalytic materials. Chemical methods have been reported to show limitations in terms of preparation and bio-compatibility. To solve these shortcomings, therefore, other technologies have been adopted; ionic liquids (eutectic solvents), chemo-enzymatic systems and chemo-enzymatic systems on a catalytic surface. The use of chemo-enzymatic systems on catalytic surfaces has proved to be suitable in solving biocompatibility and stability problems and correspondingly increasing the yield of esters formed. Therefore, finding an improved catalytic surface, and the sustainable optimal reaction conditions for enzymes will be vital to improving sugar ester conversion. This study highlights the different catalytic advances employed in the esterification of SEs.

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 250
Author(s):  
Wenlong Zhu ◽  
Miaomiao Gao ◽  
Biqiang Chen ◽  
Tianwei Tan ◽  
Hui Cao ◽  
...  

Mannose-6-phosphate (M6P) is involved in many metabolic pathways in life, and it has important applications in the treatment of diseases. This study explored a cost-effective enzyme catalytic synthesis method of M6P, using polyphosphate-dependent mannose kinase from Arthrobacter species. This synthesis uses polyphosphate to replace expensive ATP, and it is greener and safer than chemical synthesis. This study investigated the effects of key factors such as metal ions, temperature, and substrate addition on this enzymatic reaction, and improved the conversion efficiency. We moreover take advantage of the response surface method to explore the best catalytic conditions synthetically. The conversion was 99.17% successful under the optimal reaction conditions. After a series of optimizations, we carried out a 200 mL scale-up experiment, which proved that the method has good prospects for industrial applications.


2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.


1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.


Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1809
Author(s):  
Zhanzhi Liu ◽  
Ying Li ◽  
Jing Wu ◽  
Sheng Chen

d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2532 ◽  
Author(s):  
Md. Nahid Pervez ◽  
Felix Y. Telegin ◽  
Yingjie Cai ◽  
Dongsheng Xia ◽  
Tiziano Zarra ◽  
...  

In this study, a Fenton-activated persulfate (Fe2+/PS) system was introduced for the efficient degradation of Mordant Blue 9 (MB 9) as a textile dye in an aqueous solution. Results showed that the degradation of MB 9 was markedly influenced by operational parameters, such as initial pH, PS concentration, Fe2+ concentration, and initial dye concentration. Optimal reaction conditions were then determined. Inorganic anions, such as Cl− and HCO3−, enhanced the degradation efficiency of MB 9 under optimal conditions. Addition of HCO3− reduced the degradation performance of MB 9, whereas the addition of Cl− increased the degradation percentage of MB 9. In addition, quenching experiments were conducted using methanol and tert-butyl alcohol as scavengers, and methanol was identified as an effective scavenger. Thus, the degradation of MB 9 was attributed to S O 4 • − and •OH radicals. The degradation and mineralization efficiency of MB 9 was significantly reduced using the conventional Fenton process i.e., Fe2+/ hydrogen peroxide (HP) because of the formation of a Fe complex during degradation. Meanwhile, the Fe2+/persulfate (PS) system improved the degradation and mineralization performance.


Author(s):  
Timothy Aljoscha Frede ◽  
Marlene Dietz ◽  
Norbert Kockmann

AbstractFast chemical process development is inevitably linked to an optimized determination of thermokinetic data of chemical reactions. A miniaturized flow calorimeter enables increased sensitivity when examining small amounts of reactants in a short time compared to traditional batch equipment. Therefore, a methodology to determine optimal reaction conditions for calorimetric measurement experiments was developed and is presented in this contribution. Within the methodology, short-cut calculations are supplemented by computational fluid dynamics (CFD) simulations for a better representation of the hydrodynamics within the microreactor. This approach leads to the effective design of experiments. Unfavourable experimental conditions for kinetics experiments are determined in advance and therefore, need not to be considered during design of experiments. The methodology is tested for an instantaneous acid-base reaction. Good agreement of simulations was obtained with experimental data. Thus, the prediction of the hydrodynamics is enabled and the first steps towards a digital twin of the calorimeter are performed. The flow rates proposed by the methodology are tested for the determination of reaction enthalpy and showed that reasonable experimental settings resulted. Graphical abstract A methodology is suggested to evaluate optimal reaction conditions for efficientacquisition of kinetic data. The experimental design space is limited by thestepwise determination of important time scales based on specified input data.


2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.


2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.


2015 ◽  
Vol 8 (8) ◽  
pp. 2283-2295 ◽  
Author(s):  
David W. Wakerley ◽  
Erwin Reisner

This perspective summarises strategies for avoiding adverse effects of O2 on H2-evolving enzymatic systems, molecular synthetic catalysts and catalytic surfaces.


2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.


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